Question

A radioactive nucleus (initial mass number A and atomic number Z) emits 3α-particles and 2 positrons. The ratio of number of neutrons to that of protons in the final nucleus will be

Answer 1

(c) : When a radioactive nucleus emits an alpha particle, its mass number decreases by 4 while the atomic number decreases by 2.
When a radioactive nucleus, emits a β⁺ particle (or positron (e⁺)) its mass number remains unchanged while the atomic number decreases by 1.